Piston; Removal - Stihl MS 441 Manual

Since the crankcase half on the
clutch side does not have a fixed
bearing seat, the oil pump must be
installed. It then serves as
reference.
– Install oil pump, b 13.3.
– Heat area around bearing seat to
approx. 150 °C (300 °F).
– Position ball bearing so that the
centring ring (arrow) points
towards the oil pump.
: Press ball bearing fully home (oil
pump).
The ball bearing must be fitted
quickly as it absorbs heat and
expands.
– Remove oil pump, b 13.3.
– Install crankshaft, b 8.6.
– Install oil seals, b 8.3.
– Reassemble all other parts in the
reverse sequence.
– Tightening torques, b 3.5.
54
8.7

Piston

8.7.1

Removal

Before removing the cylinder,
decide whether the crankshaft is to
be removed, b 8.6.
– Remove cylinder, b 8.5.
: Prise hookless snap rings on
both sides out at the recess
(arrow) with a suitable tool.
1
: Apply assembly drift (1)
1111 893 4700.
2
: Push piston pin (1) out of the
piston with assembly drift (2)
1111 893 4700.
If the piston pin is stuck, it can be
loosened by lightly tapping the
assembly drift with a hammer. The
piston must be steadied during this
process to ensure that jolts are not
transmitted to the con-rod.
: Remove piston (1) from con-rod.
– Examine piston rings, replace
if necessary, b 8.8.
MS 441, MS 441 C
1
1